The present invention relates generally to impact warning systems for truck and trailer combinations, and more particularly to a system for warning the driver of a pick-up truck should the front section of a fifth wheel trailer pivotally supported on a hitch mounted in the bed of the truck approach a point of impact with the cab of the truck during a turning maneuver of the truck and trailer.
Over the last several decades, campers and travel trailers have become quite popular with those individuals who enjoy traveling but wish to avoid the inconveniences and well known problems of trying to find available and affordable hotel/motel accommodations at the right locations and at the right times, of locating safe and clean eating and rest facilities along the road, and of having to pack and unpack clothing, food and other personal items on a daily basis. Use of a camper or travel trailer provides individuals with a convenient, affordable, safe and comfortable home away from home wherever they may decide to go, wherever they may choose to stop or camp for sightseeing or rest, whatever the purpose of the trip or however long or short the tripxe2x80x94whether to enjoy an overnight visit to a local lake or forest for fishing or hunting or undertake an extended tour.
Until recent years, the most common travel trailer has been the type which is simply hitched behind and pulled by an automobile or other vehicle. During recent years, however, the combination of a pick-up truck with a fifth wheel trailer has proven to be an increasingly popular and growing alternative. For essentially the same amount of usable interior space, a pick-up truck with a fifth wheel trailer will provide a shorter overall length than the combination of a truck or automobile and the usual pulled travel trailer. Any overall length reduction, of course, will provide distinct advantages not only because of better stability on the road at various speeds and under various road and environmental conditions, but because of increased ease of handling while trying to jockey back and forth into or out of a tight parking area or navigate around a sharp corner.
As is well known to those in the art, in equipping a pick-up truck with a hitch suitable for receipt of the kingpin of a fifth wheel trailer, the hitch must be mounted in the truck bed ahead of the truck""s rear axle. Otherwise, if the hitch should be mounted over or to the rear of the rear axle, the weight placed on the hitch by the front section of the trailer will tend to lift the front wheels of the truck off of the road surface and thus cause loss of traction or otherwise interfere with steering ability of the truck, particularly in going over a dip or bump. Any such loss of steering traction, of course, would result in unacceptable safety concerns.
In pick-up trucks with relatively long beds, the necessary positioning of the hitch forwardly of the rear axle normally is not a problem. In the case of a truck with a short bed, however, a complication often will develop as the space forwardly of the hitch may not be sufficient for the front section of the trailer to rotate without impacting on the rear of the truck cab during a sharp turn of the truck-trailer unit. Particularly, in trying to navigate a sharp curve or to jockey a truck and attached fifth wheel trailer back and forth into or from a limited space under poor light conditions, the driver of a short-bed pick-up may not realize that the front section of the trailer is in imminent danger of striking the cab until after a strike and resultant damage to the cab and perhaps also to the trailer have occurred.
While an experienced truck driver might be expected to be cognizant of and thus on guard against an inadvertent impact of the type described above, unfortunately even the experienced truck/trailer owner or user can find it quite difficult to observe the position of the front section of the trailer closely enough to prevent any possible impact with the cab while simultaneously trying to watch both sides of the truck and trailer to avoid trees, buildings, moving people or animals, or other vehicles in trying to back from or enter a tight area or navigate a sharp turn. And for a new or inexperienced driver, such circumstances would almost be assured of generating a problem. Unfortunately, for this reason, many a trip or outing has suddenly and expensively been spoiled.
Short bed trucks are now quite popular as they not only will provide a shorter and more maneuverable vehicle but permit use of an extended cab without an increase in overall vehicle length. Few such trucks are believed purchased specifically for use with a fifth wheel trailer, and even where such use may be anticipated many purchasers do not seem to be aware of the potential trailer impact problem involving a short bed truck. Thus, the problem of potential impact damage when a short bed pick-up truck is combined with a fifth wheel trailer is likely to continue occurring with a high percentage of such trucks.
The above discussed problem of accidental impact between the front section of a fifth wheel trailer and the cab of a pickup truck has been recognized in the past by those in the field, and several proposals have been made for its solution. Examples of such proposed solutions include mechanisms for moving the weight bearing hitch point for the trailer back and forth in the truck bed in response to the need for space during turns, and for shifting the weight bearing point of the hitch rearwardly of the rear axle using a beam or arm projecting rearwardly over the axle. For various reasons, however, none of these prior proposals have met with any significant commercial acceptance or success. Accordingly, until development of the present invention, no truly satisfactory solution to the above discussed impact problem has been advanced.
Accordingly, it is an object of this invention to provide a system which is usable with any pickup truck to warn the driver of the truck if the front section of a fifth wheel trailer hitched to the bed of the truck is approaching a point of impact with the cab of the truck during a turning maneuver of the truck.
Another object of the present invention is the provision of a warning system of the type described hereabove comprised of components which are readily mounted on any pickup truck at the time a fifth wheel trailer is hitched to such truck and which are readily removed from the truck when the trailer is unhitched from the truck, yet which may be left on the truck after removal of the trailer without danger of damage either to the components or the truck.
A still further object of this invention is to provide a warning system of the type described hereabove comprised of components which may be moved between and mounted on various pickup trucks and which are readily adjustable to assure effective operation when used with various trailers having front sections of various sizes and configurations.
An additional objective of the present invention is the provision of a warning system of the type described above which is simple in design and structure, is inexpensive to produce and maintain, is easy and convenient to use, and is rugged and reliable in operation.
These and other objects, features and advantages of the present invention will be apparent from the following summary and description of the preferred embodiment when taken in conjunction with the accompanying drawings.
As pointed out hereabove, it is difficult to use one of today""s short bed pickup trucks to haul a fifth wheel trailer without running the very real danger of damaging either or both the back of the cab and/or the front section of the trailer as a result of impact between the cab and front section as the unit is maneuvered through sharp turns or into or out of limited spaces. Not only is this currently a real problem, but with the growing popularity of short bed pickup trucks and the increasing use of fifth wheel trailers for travel and camping purposes, the problem can be expected to grow rapidly.
The present invention provides a unique system which not only successfully addresses the need for warning the driver of a truck of an imminent impact problem so that the problem can be averted, but it accomplishes this function in a simple and effective manner using structure which is inexpensive, reliable and easily placed on the truck and adjusted to function properly with any fifth wheel trailer which may be hitched to the bed of the truck.
These and other features and advantages are provided in the present invention by a unique combination of alarm and warning means wherein the warning means comprises a device placed in the cab of the truck and provided with at least one transducer capable of converting an electrical signal into an audible, visible and/or other humanly perceptible event. This warning device may be mounted permanently or semi-permanently in the cab with wiring appropriately routed and hidden, or it may simply be hung temporarily in the cab with wires entering through a window or door opening.
The warning device is activated upon receipt of an electrical signal from the alarm means mounted on the wall of the truck bed proximate the back of the truck cab. As will be explained in more detail hereinafter, while the alarm means may consist of a single device, in the illustrated embodiment it comprises two alarm assemblies removably clamped on the top edge of the front wall of the bed. Each alarm assembly is provided with a mounting member having a generally horizontally disposed upper support plate with a pair of dependent legs straddling the top edge of the front wall. The leg disposed on the inside of the bed carries a threaded clamp which is manually tightened to secure the assembly on the wall. Carried on the upper support plate is a positioning mechanism comprising a first element mounted for limited rotation relative to the support plate and a second element mounted for limited linear movement relative to the first element and the support plate.
Carried on the positioning mechanism is a contact member normally biased in a substantially vertical position. Also mounted on the positioning mechanism is an electrical switch which is operatively engaged with the contact member and which, with appropriate wiring, forms a part of an electrical circuit releasably connected to the power system of the truck and to the transducer(s) of the warning device. The switch normally is held in an open position isolating the transducer(s) from the truck""s power system but is movable in response to movement of the contact member to a closed position to connect the transducer(s) to the power system to actuate the transducer(s) and gain the attention of the driver of the truck.
The first and second elements of the positioning mechanism are manually adjustable relative to the support plate and mounting member to move the vertically disposed contact member to a position spaced a predetermined distance from the back of the cab and located at a point where it will intercept the adjacent corner of the front section of the trailer should the corner rotate to that point as the truck and trailer navigate a turn. After the contact member has been positioned properly, the first and second elements are releasably clamped against further movement relative to each other and the mounting member by manually rotatable screw locking members.
It will be understood, of course, that the same positioning and adjusting procedure is to be followed with each of the two alarm assemblies mounted on the front wall of the truck bed whereby both back sides of the truck cab will be protected by the alarm system should the truck driver inadvertently turn too sharply in either direction.
In a preferred embodiment of this invention, the contact member consists of two parts, including a base portion pivoted on the second element of the positioning mechanism and an upper arm portion removably attached to the base portion. As will be understood, this two part structure not only permits easy adjustment of the upper arm portion relative to the base portion but convenient replacement of the upper arm portion with another upper arm portion in the event of damage or in case a different arm length or configuration might be needed for a particular truck-trailer combination.
The switch is carried on a mount plate which is fixed to the second element of the positioning mechanism. The switch includes an operating member resiliently biased into contact with the base portion of the contact member for movement with the contact member between a retracted position in which the switch is held open and an extended position in which the switch is closed. In the closed position, the switch completes an electrical circuit between the truck""s power source and the transducer(s) in the warning device to create the alarm signal, indicative of displacement of the contact member from its substantially vertical position as a result of contact with a corner of the front section of the trailer. This alarm signal, of course, would alert the driver of the truck of an impending impact between the back surface of the cab and a corner of the trailer""s front section in time to reduce the turning radius and thus avoid the potential impact problem.
While it would be possible to provide a warning device as a part of each of the two alarm assemblies used in the system discussed above and to mount both devices within the cab of a truck being fitted with a warning system according to this invention, it is preferred that only one warning device be used. Accordingly, in preparing the electrical wiring for the circuit to be used in the present system, the warning device preferably is not xe2x80x9chardxe2x80x9d wired with the switch of either alarm assembly, but rather is connected with the switches either through appropriate plugs and receptacles or indirectly through common lines from a connection box located outside of the cab. Connection with the power system of the truck may then be made using a plug sized to fit into the usual cigarette lighter receptacle or other convenient means of removably connecting the warning system to the truck""s power source.
As pointed out hereabove, the present invention is not limited to a warning system utilizing two separate alarm assemblies as the alarm means may comprise a single unit which extends across the front wall of the bed of a pickup truck. In this event, the unit preferably would have a centrally located switch and a contact member mounted at each end of the unit on an appropriate positioning mechanism, with the contact members being mounted on a common pivot bar or like element whereby movement of either contact member in response to contact with the front section of a trailer would operate the switch to activate the warning device to alert the driver of an imminent problem.
It should be pointed out that throughout the specification and claims of this application, the words xe2x80x9cfrontxe2x80x9d and xe2x80x9cforwardxe2x80x9d and terms of similar import are to be taken as meaning a direction oriented generally toward the front end of a truck, and the words xe2x80x9cback,xe2x80x9d xe2x80x9crear,xe2x80x9d xe2x80x9crearwardxe2x80x9d and terms of similar import are to be taken as meaning a direction oriented generally toward the back end of a truck.